Google Voice is an awesome idea and piece of software (if you are willing to give away more self information to Google than you already have). It is not a VOIP service like Google Talk; it is a call management service. It will always cost you money in one way or the other (cellular minutes or data) and you will not be able to make free calls. If you consider cellular data to be free or use wifi, there are workarounds to make it free like using Talkatone or GrooVe IP or other third party apps. These applications use Google Talk free calling feature (VOIP) along with Google Voice, which integrates with Google Talk, to make free calls using only data. Keep in mind that by using more services, you are distributing your own information all over the Internet companies.

So. Google by itself doesn’t allow free calls on the cellphones. Google allows free calls on the computer using Google Talk. Third party applications allow free calls on the cellphone using the cellular data and Google Voice + Talk.

Are text messages free on Google Voice? Yes. Whether you use it from a cellphone or a computer, messages are free.

How does Google Voice use your minutes or data to send/make or receive calls/texts? From what I read about it on Google forums, I put together a simple diagram. Notice the color coding in the image.

Google Voice and Carrier Minutes or Data

Incoming and voicemails

Google transfers the call to your cellphone which costs carrier minutes. If you are using Google for voicemail, whenever you miss a call, your carrier forwards the call to Google voicemail. Call forwarding uses carrier minutes.

Outgoing and voicemails

First, if you notice a voicemail and call your voicemail box, you are using carrier minutes. Second, whenever you initiate a outgoing call, Google Voice uses data (a tiny bit) to connect to the server and initiates the call by calling your cellphone, which costs carrier minutes, and then connecting the call to the other phone.

Text message and voicemail

Why is voicemail mentioned here? Because Google transcribes the voicemails which can be accessed as email or text messages. Now, all text messaging happens over the cellular data or wifi and it doesn’t use any cellular minutes.

Why did I say I don’t know how Google Voice works? Because I really don’t know how it works. I just know how they use the carrier minutes/texts (on high level) and I hope by now you do too. Let me know in the comments below.

Note about setup:

Using Google Voice number as primary and transferring calls to your cellphone number.

Disabled the carrier voicemail and set it to forward to Google Voice voicemail.